Stamping process for metal objects

ABSTRACT

In a process for producing metallic objects by stamping blanks located side-by-side in echelon formation in a metal strip which is then advanced through shaping means for executing shaping operations there is provided blanks to be stamped by cutting said strip along portions of the true peripheries of the objects so that said blanks remain connected to spacer web portions of said strip solely by connecting elements maintaining said blanks within said strip during the subsequent shaping operations and until final separation of the finished objects.

United States Patent Maurice Lachaussee 360. rue de IYser. Ans-Lez-Llege, Belgium; Andre Maigret. 4, Avenue de la Grange,

[72] inventors Saint Maur Des Fosses, France [21] Appl. No. 755,214 [22] Filed Aug. 26, 1968 [45] Patented Aug. 3, 1971 [32] Priority Sept. 15, 1967 [33] Belgium [31 1 41,474

[54] STAMPING PROCESS FOR METAL OBJECTS 4 Claims, 1 Drawing Fig.-

[52] U.S. Cl 72/339, 29/190 [51] Int. Cl 821d 28/00. 1321c 1/00 [50] Field at Search 72/339.

[56] Reierences Cited UNITED STATES PATENTS 2,309,942 2/1943 Ekstedt et al. 72/335 3,338,084 '7/l967 Stcgman 72/335 2,846,902. 0/1958 Cowley H 72/335 36.4%,?! 2/1970 Cribbings 72/339 Primary Examiner Charles W. Lanham Assistant Esdminsr ll. M. Rogers Anamey Young ds Thompson ABSTRACT: in a process for producing metallic objects by stamping blanks located side-by-side in echelon formation in a metal strip which is then advanced through shaping means for executing shaping operations there is provided blanks to be stamped by cutting said strip along portions of the true peripheries of the objects so that said blanks remain connected to spacer web portions of said strip solely by connecting elements maintaining said blanks within said atrip during the subsequent ehaping operations and until final separation of the finished objects.

The present invention relates to a stamping process for producing metallic objects from blanks formed in a strip of metal.

Metal products such as basins, cupels and the like are conventionally manufactured by deep-stamping of appropriate blanks.

In one known method, the blanks cut from a sheet are placed successively by hand in a press which effects the entire stamping in a single operation. This method, although cheap, involves a considerable expenditure in handling and personnel. Its output rate is low and it is wasteful owing to the cutting operations involved.

In another method, the blanks are cut from the sheet and are transported from one working position to another by means of tongs. While the machine applying this method permits savings in personnel, it is complex and in consequence also costly. Moreover, it works of necessity at slow speeds, which again limits production and it can work only one piece at a time.

In a third method, the blanks remain in the metal strip in which they have been formed and the strip is passed step by step under various tools which execute different shaping operations, at the end of which the finished pieces are extracted from the strip. The application of this method necessitates the provision around the contour of the useful portion of the blank from which the object is stamped of an annular crown of a certain width which, after execution of the partial cuts respectively along its periphery and along the periphery of the useful portion of the blank, forms retaining tongues connecting said useful portion of the blank to the web portions which interconnects the objects and holds them within the strip until the final separation.

This method is advantageous because it makes possible the simultaneous stamping of several pieces in a fully automatic operation and at high speeds, but nevertheless its material consumption is high by reason of the annular crown which serves only to form the retaining tongues and then goes to waste.

The present invention consists in a process for producing metallic objects by stamping blanks located side by side in echelon formation in ametal strip which is then advanced through means executing a shaping operation, characterized in that the blanks to be stamped are formed by cutting the strip along portions of the true peripheries of the objects so that the blanks remain connected to spacer web portions of the strip solely by connecting elements which maintain the blanks within the strip during the subsequent shaping operation and until final separation of the finished objects.

According to a preferred feature of this process, the webs separating the echeloned blanks are provided at intervals with separating cuts which may be holes or slots framing said blanks.

Moreover, circular blanks are preferably partly out along their periphery, with three slots arranged at 120 relative to each other, and which are separated from each other by the connecting zones of the webs.

The present invention will be more easily understood by the description hereinafter given with reference to the accompanying drawing which illustrates one application of the process according to the invention.

The FIGURE shows a partial schematical plan view of a sheet metal strip during the operations for shaping basins by stamping.

A sheet metal strip 1, e.g., copper, is introduced into a machine which is not illustrated, being known, and is passed step by step under a series of tools arranged at fixed stations which execute the various operations necessary for the shaping of the objects, e.g., basins. In the example illustrated, the strip is sufficiently wide for producing the objects simultaneously in two adjacent rows.

To this end, holes 2a, 2b, 2c are drilled previously in these portions of the strip where the blank-separating webs are situated, said webs being referred to hereinafter as spacer webs. The holes are arranged in parallel lines 20, 2b, 2c and, in two lines 2a and 2b the holes are in lateral alignment, whereas in the third line 2c they are in echelon arrangement with respect to the holes in lines 2a and 212 so as to frame the sheet portions to be stamped, hereinafter referred to as blanks. Each of these blanks 3 comprises only a useful sheet portion sufficient for the shaping of one object, i.e., each of these blanks 3 has a diameter which exactly equals the diameter of a sheet portion necessary to form a basin. Along their periphery, the blanks 3 are formed by partial cuts in the form of three slots 4. These slots 4 are spaced at relative to each other, which leaves three attaching portions 5 connecting the blanks 3 to the spacer webs 6, of a triangular general form. These connecting portions, are spaced at about 120 relative to each other and constitute the sole retaining elements of the blanks 3 to the spacer webs 6. In this manner, the retaining tongues of the known process are dispensed with.

The method according to the invention, owing to the elimination of the aforementioned annular crown or flange surrounding each blank, results in a saving in material. Immediately after provision of the peripheral slots 4, the blanks 3 connected to the spacer webs undergo the various stamping operations to form the basins 3a which remain connected by the connections 5 to the webs 6 and to the lateral zones la, the blanks 3 remaining within the strip during said operations.

As a resultof the deformation of the blanks, these stamping operations produce at the location of the peripheral slots 4, apertures having the form of half-crescents 7 and crescents 8, partly surrounding the basins 3a. The FIGURE shows that the half-crescent-shaped apertures 7 communicate with the holes 2b, 2c. When the basins are finished, they are separated from the remaining sheet portions which are the lateral zones 1a and the spacer webs 6 and which constitute the waste.

In the foregoing the invention has been described as applied to two rows of blanks, but is not limited to this formation and can be applied to the manufacture of stamped products of circular or any other shape from two or more rows of blanks. Moreover, the holes surrounding the blanks may be of any shape or replaced by slots, for example in the form of threepoint stars.

What I claim is:

1. A process for producing metallic objects from circular blanks located side by side in staggered echelon formation in a metal strip, comprising cutting lines of holes in the strip tangent to the circular blanks to be formed so as to frame strip portions corresponding to the circular blanks to be formed, thereafter cutting said strip along portions only of the circular periphery of the blanks to be formed while leaving spacer web portions of said strip which form the sole connections between said blanks and said strip, thereafter advancing said strip through shaping means for executing shaping operations on said blanks so as to obtain finished metallic objects whose peripheries coincide with said peripheries of said blanks, and then separating said finished objects from said strip.

2. A process as claimed in claim 1, in which said blanks each cut along three arcs equally spaced from each other about the periphery of the blank, said spacer web portions being disposed at the ends of said arcs.

3. A process as claimed in claim 1, in which said holes are circular.

4. A process as claimed in claim I, in which said holes are each tangent to three blanks and in which the cuts that extend along the periphery of the blanks form with each hole a three branch star. 

1. A process for producing metallic objects from circular blanks located side by side in staggered echelon formation in a metal strip, comprising cutting lines of holes in the strip tangent to the circular blanks to be formed so as to frame strip portions corresponding to the circular blanks to be formed, thereafter cutting said strip along portions only of the ciRcular periphery of the blanks to be formed while leaving spacer web portions of said strip which form the sole connections between said blanks and said strip, thereafter advancing said strip through shaping means for executing shaping operations on said blanks so as to obtain finished metallic objects whose peripheries coincide with said peripheries of said blanks, and then separating said finished objects from said strip.
 2. A process as claimed in claim 1, in which said blanks each cut along three arcs equally spaced from each other about the periphery of the blank, said spacer web portions being disposed at the ends of said arcs.
 3. A process as claimed in claim 1, in which said holes are circular.
 4. A process as claimed in claim 1, in which said holes are each tangent to three blanks and in which the cuts that extend along the periphery of the blanks form with each hole a three-branch star. 